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Rahmani A, McMillen A, Allen E, Minervini C, Chew YL. Behavioral Tests for Associative Learning in Caenorhabditis elegans. Methods Mol Biol 2024; 2746:21-46. [PMID: 38070077 DOI: 10.1007/978-1-0716-3585-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Learning is critical for survival as it provides the capacity to adapt to a changing environment. At the molecular and cellular level, learning leads to alterations within neural circuits that include synaptic rewiring, synaptic plasticity, and protein level/gene expression changes. There has been substantial progress in recent years on dissecting how learning and memory is regulated at the molecular and cellular level, including the use of compact invertebrate nervous systems as experimental models. This progress has been facilitated by the establishment of robust behavioral assays that generate a quantifiable readout of the extent to which animals learn and remember. This chapter will focus on protocols of behavioral tests for associative learning using the nematode Caenorhabditis elegans, with its unparalleled genetic tractability, compact nervous system of ~300 neurons, high level of conservation with mammalian systems, and amenability to a suite of behavioral tools and analyses. Specifically, we will provide a detailed description of the methods for two behavioral assays that model associative learning, one measuring appetitive olfactory learning and the other assaying aversive gustatory learning.
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Affiliation(s)
- Aelon Rahmani
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Anna McMillen
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Ericka Allen
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Caitlin Minervini
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Yee Lian Chew
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia.
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2
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Gadenne MJ, Hardege I, Yemini E, Suleski D, Jaggers P, Beets I, Schafer WR, Chew YL. Neuropeptide signalling shapes feeding and reproductive behaviours in male Caenorhabditis elegans. Life Sci Alliance 2022; 5:5/10/e202201420. [PMID: 35738805 PMCID: PMC9233197 DOI: 10.26508/lsa.202201420] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 06/03/2022] [Accepted: 06/03/2022] [Indexed: 11/24/2022] Open
Abstract
LURY-1 peptides are expressed in distinct cells in different sexes and have sex-specific effects on feeding and mating, providing further evidence for the role of neuromodulators in sexual dimorphism. Sexual dimorphism occurs where different sexes of the same species display differences in characteristics not limited to reproduction. For the nematode Caenorhabditis elegans, in which the complete neuroanatomy has been solved for both hermaphrodites and males, sexually dimorphic features have been observed both in terms of the number of neurons and in synaptic connectivity. In addition, male behaviours, such as food-leaving to prioritise searching for mates, have been attributed to neuropeptides released from sex-shared or sex-specific neurons. In this study, we show that the lury-1 neuropeptide gene shows a sexually dimorphic expression pattern; being expressed in pharyngeal neurons in both sexes but displaying additional expression in tail neurons only in the male. We also show that lury-1 mutant animals show sex differences in feeding behaviours, with pharyngeal pumping elevated in hermaphrodites but reduced in males. LURY-1 also modulates male mating efficiency, influencing motor events during contact with a hermaphrodite. Our findings indicate sex-specific roles of this peptide in feeding and reproduction in C. elegans, providing further insight into neuromodulatory control of sexually dimorphic behaviours.
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Affiliation(s)
- Matthew J Gadenne
- Molecular Horizons, University of Wollongong and Illawarra Health and Medical Research Institute, Wollongong, Australia
| | - Iris Hardege
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Eviatar Yemini
- Department of Neurobiology, UMass Chan Medical School, Worcester, MA, USA
| | - Djordji Suleski
- Molecular Horizons, University of Wollongong and Illawarra Health and Medical Research Institute, Wollongong, Australia
| | - Paris Jaggers
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Isabel Beets
- Department of Biology, KU Leuven, Leuven, Belgium
| | - William R Schafer
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK.,Department of Biology, KU Leuven, Leuven, Belgium
| | - Yee Lian Chew
- Flinders Health and Medical Research Institute and College of Medicine and Public Health, Flinders University, Adelaide, Australia
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3
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Claesson K, Chew YL, Ecroyd H. Exploiting flow cytometry for the unbiased quantification of protein inclusions in Caenorhabditis elegans. J Neurochem 2022; 161:281-292. [PMID: 35170035 PMCID: PMC9541147 DOI: 10.1111/jnc.15591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 01/28/2022] [Accepted: 02/12/2022] [Indexed: 11/29/2022]
Abstract
The aggregation of proteins into inclusions or plaques is a prominent hallmark of a diverse range of pathologies including neurodegenerative diseases. The quantification of such inclusions in Caenorhabditis elegans models of aggregation is usually achieved by fluorescence microscopy or other techniques involving biochemical fractionation of worm lysates. Here, we describe a simple and rapid flow cytometry-based approach that allows fluorescently tagged inclusions to be enumerated in whole worm lysate in a quantitative and unbiased fashion. We demonstrate that this technique is applicable to multiple C. elegans models of aggregation and importantly, can be used to monitor the dynamics of inclusion formation in response to heat shock and during ageing. This includes the characterisation of physicochemical properties of inclusions, such as their apparent size, which may reveal how aggregate formation is distinct in different tissues or at different stages of pathology or ageing. This new method can be used as a powerful technique for the medium- to high-throughput quantification of inclusions in future studies of genetic or chemical modulators of aggregation in C. elegans.
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Affiliation(s)
- Kristian Claesson
- Molecular Horizons and School of Chemistry and Molecular BioscienceUniversity of WollongongWollongongNSWAustralia
- Illawarra Health & Medical Research InstituteWollongongNew South WalesAustralia
| | - Yee Lian Chew
- Molecular Horizons and School of Chemistry and Molecular BioscienceUniversity of WollongongWollongongNSWAustralia
- Illawarra Health & Medical Research InstituteWollongongNew South WalesAustralia
- Flinders Health and Medical Research Institute, College of Medicine and Public HealthFlinders UniversityBedford ParkSouth AustraliaAustralia
| | - Heath Ecroyd
- Molecular Horizons and School of Chemistry and Molecular BioscienceUniversity of WollongongWollongongNSWAustralia
- Illawarra Health & Medical Research InstituteWollongongNew South WalesAustralia
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4
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Wang Z, Zheng P, Chen X, Xie Y, Weston-Green K, Solowij N, Chew YL, Huang XF. Cannabidiol induces autophagy and improves neuronal health associated with SIRT1 mediated longevity. GeroScience 2022; 44:1505-1524. [PMID: 35445360 PMCID: PMC9213613 DOI: 10.1007/s11357-022-00559-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 03/30/2022] [Indexed: 11/30/2022] Open
Abstract
Autophagy is a catabolic process to eliminate defective cellular molecules via lysosome-mediated degradation. Dysfunctional autophagy is associated with accelerated aging, whereas stimulation of autophagy could have potent anti-aging effects. We report that cannabidiol (CBD), a natural compound from Cannabis sativa, extends lifespan and rescues age-associated physiological declines in C. elegans. CBD promoted autophagic flux in nerve-ring neurons visualized by a tandem-tagged LGG-1 reporter during aging in C. elegans. Similarly, CBD activated autophagic flux in hippocampal and SH-SY5Y neurons. Furthermore, CBD-mediated lifespan extension was dependent on autophagy genes (bec-1, vps-34, and sqst-1) confirmed by RNAi knockdown experiments. C. elegans neurons have previously been shown to accumulate aberrant morphologies, such as beading and blebbing, with increasing age. Interestingly, CBD treatment slowed the development of these features in anterior and posterior touch receptor neurons (TRN) during aging. RNAi knockdown experiments indicated that CBD-mediated age-associated morphological changes in TRNs require bec-1 and sqst-1, not vps-34. Further investigation demonstrated that CBD-induced lifespan extension and increased neuronal health require sir-2.1/SIRT1. These findings collectively indicate the anti-aging benefits of CBD treatment, in both in vitro and in vivo models, and its potential to improve neuronal health and longevity.
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Affiliation(s)
- Zhizhen Wang
- Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, NSW, Australia.,Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Peng Zheng
- Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Xi Chen
- Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Yuanyi Xie
- Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Katrina Weston-Green
- Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, NSW, Australia.,Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia.,Molecular Horizons, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Nadia Solowij
- Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, NSW, Australia.,Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia.,School of Psychology, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Yee Lian Chew
- Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia. .,Molecular Horizons, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, 2522, Australia. .,Flinders Health and Medical Research Institute and College of Medicine and Public Health, Flinders University, Bedford Park, South Australia, 5042, Australia.
| | - Xu-Feng Huang
- Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, NSW, Australia. .,Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia. .,Molecular Horizons, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, 2522, Australia.
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Rahmani A, Chew YL. Investigating the molecular mechanisms of learning and memory using Caenorhabditis elegans. J Neurochem 2021; 159:417-451. [PMID: 34528252 DOI: 10.1111/jnc.15510] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 08/15/2021] [Accepted: 09/08/2021] [Indexed: 11/30/2022]
Abstract
Learning is an essential biological process for survival since it facilitates behavioural plasticity in response to environmental changes. This process is mediated by a wide variety of genes, mostly expressed in the nervous system. Many studies have extensively explored the molecular and cellular mechanisms underlying learning and memory. This review will focus on the advances gained through the study of the nematode Caenorhabditis elegans. C. elegans provides an excellent system to study learning because of its genetic tractability, in addition to its invariant, compact nervous system (~300 neurons) that is well-characterised at the structural level. Importantly, despite its compact nature, the nematode nervous system possesses a high level of conservation with mammalian systems. These features allow the study of genes within specific sensory-, inter- and motor neurons, facilitating the interrogation of signalling pathways that mediate learning via defined neural circuits. This review will detail how learning and memory can be studied in C. elegans through behavioural paradigms that target distinct sensory modalities. We will also summarise recent studies describing mechanisms through which key molecular and cellular pathways are proposed to affect associative and non-associative forms of learning.
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Affiliation(s)
- Aelon Rahmani
- Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
| | - Yee Lian Chew
- Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
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6
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Wang Z, Zheng P, Xie Y, Chen X, Solowij N, Green K, Chew YL, Huang XF. Cannabidiol regulates CB1-pSTAT3 signaling for neurite outgrowth, prolongs lifespan, and improves health span in Caenorhabditis elegans of Aβ pathology models. FASEB J 2021; 35:e21537. [PMID: 33817834 DOI: 10.1096/fj.202002724r] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/22/2021] [Accepted: 03/03/2021] [Indexed: 12/12/2022]
Abstract
Cannabidiol (CBD), a phytocannabinoid from the Cannabis sativa plant, exhibits a broad spectrum of potential therapeutic properties for neurodegenerative diseases. An accumulation of amyloid-β (Aβ) protein is one of the most important neuropathology in neurodegenerative diseases like Alzheimer's disease (AD). Data on the effect of CBD on the amelioration of Aβ-induced neurite degeneration and its consequences of life and health spans is sparse. This study aimed to investigate the effects of CBD on neurite outgrowth in cells and lifespan and health span in Caenorhabditis elegans (C. elegans). In human SH-SY5Y neuronal cells, CBD prevented neurite lesion induced by Aβ1-42 and increased the expression of fatty acid amide hydrolase (FAAH) and cannabinoid receptor 1 (CB1R). Furthermore, CBD both protected the reduction of dendritic spine density and rescued the activity of synaptic Ca2+ /calmodulin-dependent protein kinase II (CaMKII) from Aβ1-42 toxicity in primary hippocampal neurons. In C. elegans, we used the transgenic CL2355 strain of C. elegans, which expresses the human Aβ peptide throughout the nervous system and found that CBD treatment extended lifespan and improved health span. The neuroprotective effect of CBD was further explored by observing the dopaminergic neurons using transgenic dat-1: GFP strains using the confocal microscope. This study shows that CBD prevents the neurite degeneration induced by Aβ, by a mechanism involving CB1R activation, and extends lifespan and improves health span in Aβ-overexpressing worms. Our findings support the potential therapeutic approach of CBD for the treatment of AD patients.
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Affiliation(s)
- Zhizhen Wang
- Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, NSW, Australia.,Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, Australia
| | - Peng Zheng
- Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, Australia
| | - Yuanyi Xie
- Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, Australia
| | - Xi Chen
- Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, Australia
| | - Nadia Solowij
- Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, NSW, Australia.,Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, Australia.,School of Psychology, University of Wollongong, Wollongong, NSW, Australia
| | - Katrina Green
- Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, NSW, Australia.,Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, Australia.,Molecular Horizons, School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia
| | - Yee Lian Chew
- Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, Australia.,Molecular Horizons, School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia
| | - Xu-Feng Huang
- Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, NSW, Australia.,Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, Australia.,Molecular Horizons, School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia
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McAlary L, Chew YL, Lum JS, Geraghty NJ, Yerbury JJ, Cashman NR. Amyotrophic Lateral Sclerosis: Proteins, Proteostasis, Prions, and Promises. Front Cell Neurosci 2020; 14:581907. [PMID: 33328890 PMCID: PMC7671971 DOI: 10.3389/fncel.2020.581907] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 09/22/2020] [Indexed: 12/13/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is characterized by the progressive degeneration of the motor neurons that innervate muscle, resulting in gradual paralysis and culminating in the inability to breathe or swallow. This neuronal degeneration occurs in a spatiotemporal manner from a point of onset in the central nervous system (CNS), suggesting that there is a molecule that spreads from cell-to-cell. There is strong evidence that the onset and progression of ALS pathology is a consequence of protein misfolding and aggregation. In line with this, a hallmark pathology of ALS is protein deposition and inclusion formation within motor neurons and surrounding glia of the proteins TAR DNA-binding protein 43, superoxide dismutase-1, or fused in sarcoma. Collectively, the observed protein aggregation, in conjunction with the spatiotemporal spread of symptoms, strongly suggests a prion-like propagation of protein aggregation occurs in ALS. In this review, we discuss the role of protein aggregation in ALS concerning protein homeostasis (proteostasis) mechanisms and prion-like propagation. Furthermore, we examine the experimental models used to investigate these processes, including in vitro assays, cultured cells, invertebrate models, and murine models. Finally, we evaluate the therapeutics that may best prevent the onset or spread of pathology in ALS and discuss what lies on the horizon for treating this currently incurable disease.
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Affiliation(s)
- Luke McAlary
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
- Molecular Horizons and School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, Australia
| | - Yee Lian Chew
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
- Molecular Horizons and School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, Australia
| | - Jeremy Stephen Lum
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
- Molecular Horizons and School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, Australia
| | - Nicholas John Geraghty
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
- Molecular Horizons and School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, Australia
| | - Justin John Yerbury
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
- Molecular Horizons and School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, Australia
| | - Neil R. Cashman
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
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De Fruyt N, Yu AJ, Rankin CH, Beets I, Chew YL. The role of neuropeptides in learning: Insights from C. elegans. Int J Biochem Cell Biol 2020; 125:105801. [DOI: 10.1016/j.biocel.2020.105801] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 06/17/2020] [Accepted: 07/06/2020] [Indexed: 12/26/2022]
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Fadda M, De Fruyt N, Borghgraef C, Watteyne J, Peymen K, Vandewyer E, Naranjo Galindo FJ, Kieswetter A, Mirabeau O, Chew YL, Beets I, Schoofs L. NPY/NPF-Related Neuropeptide FLP-34 Signals from Serotonergic Neurons to Modulate Aversive Olfactory Learning in Caenorhabditis elegans. J Neurosci 2020; 40:6018-6034. [PMID: 32576621 PMCID: PMC7392509 DOI: 10.1523/jneurosci.2674-19.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 04/26/2020] [Accepted: 06/12/2020] [Indexed: 02/03/2023] Open
Abstract
Aversive learning is fundamental for animals to increase chances of survival. In addition to classical neurotransmitters, neuropeptides have emerged to modulate such complex behaviors. Among them, neuropeptide Y (NPY) is well known to promote aversive memory acquisition in mammals. Here we identify an NPY/neuropeptide F (NPF)-related neuropeptide system in Caenorhabditis elegans and show that this FLP-34/NPR-11 system is required for learning negative associations, a process that is reminiscent of NPY signaling in mammals. The Caenorhabditis elegans NPY/NPF ortholog FLP-34 displays conserved structural hallmarks of bilaterian-wide NPY/NPF neuropeptides. We show that it is required for aversive olfactory learning after pairing diacetyl with the absence of food, but not for appetitive olfactory learning in response to butanone. To mediate diacetyl learning and thus integrate the aversive food context with the diacetyl odor, FLP-34 is released from serotonergic neurons and signals through its evolutionarily conserved NPY/NPF GPCR, NPR-11, in downstream AIA interneurons. NPR-11 activation in the AIA integration center results in avoidance of a previously attractive stimulus. This study opens perspectives for a deeper understanding of stress conditions in which aversive learning results in excessive avoidance.SIGNIFICANCE STATEMENT Aversive learning evolved early in evolution to promote avoidance of dangerous and stressful situations. In addition to classical neurotransmitters, neuropeptides are emerging as modulators of complex behaviors, including learning and memory. Here, we identified the evolutionary ortholog of neuropeptide Y/neuropeptide F in the nematode Caenorhabditis elegans, and we discovered that it is required for olfactory aversive learning. In addition, we elucidated the neural circuit underlying this avoidance behavior, and we discovered a novel coordinated action of Caenorhabditis elegans neuropeptide Y/neuropeptide F and serotonin that could aid in our understanding of the molecular mechanisms underlying stress disorders in which excessive avoidance results in maladaptive behaviors.
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Affiliation(s)
- Melissa Fadda
- Department of Biology, KU Leuven, Leuven, 3000, Belgium
| | | | | | - Jan Watteyne
- Department of Biology, KU Leuven, Leuven, 3000, Belgium
| | | | | | | | | | - Olivier Mirabeau
- Genetics and Biology of Cancers Unit, Institut Curie, Institut National de la Santé et de la Recherche Médicale U830, Paris Sciences et Lettres Research University, Paris, 75005, France
| | - Yee Lian Chew
- Illawarra Health & Medical Research Institute School of Chemistry & Molecular Bioscience, University of Wollongong, Wollongong, 2522 New South Wales, Australia
| | - Isabel Beets
- Department of Biology, KU Leuven, Leuven, 3000, Belgium
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Cho Y, Lee SA, Chew YL, Broderick K, Schafer WR, Lu H. Multimodal Stimulation in a Microfluidic Device Facilitates Studies of Interneurons in Sensory Integration in C. elegans. Small 2020; 16:e1905852. [PMID: 32003130 PMCID: PMC7720847 DOI: 10.1002/smll.201905852] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 11/30/2019] [Indexed: 06/10/2023]
Abstract
Animals' perception and behavior involve integration of multiple sensory modalities. Caenorhabditis elegans is a useful model for studying multimodal sensory integration, as it has well-characterized neuronal circuits in a relatively simple nervous system. However, most studies based on functional imaging have only been conducted on single modal stimuli, because well-controlled multimodal experiments for C. elegans are technically difficult. For instance, no single systems currently deliver precise stimuli with spatial, temporal, and intensity control, despite prior hypotheses that interneurons do integrate these sensory inputs to control behavior. Here, a microfluidic platform that can easily deliver spatially and temporally controlled combination stimuli to C. elegans is presented. With this platform, both sensory and interneuron activity is measured in response to mechanical and chemical stimulations in a quantitative and high-throughput manner. It is found that the activity of command interneuron PVC can be modulated by prior stimulation both within the same and across different modalities. The roles of monoaminergic and peptidergic signaling are further examined on the process of multimodal integration through PVC activity. The approach exemplified here is envisioned to be broadly applicable in different contexts to elucidate underlying mechanisms and identify genes affecting multisensory integration.
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Affiliation(s)
- Yongmin Cho
- School of Chemical & Biomolecular EngineeringGeorgia Institute of TechnologyAtlantaGA30332USA
- Present address:
Department of Systems BiologyHarvard Medical SchoolBostonMA02115USA
| | - Sol Ah Lee
- School of Chemical & Biomolecular EngineeringGeorgia Institute of TechnologyAtlantaGA30332USA
| | - Yee Lian Chew
- Neurobiology DivisionMedical Research Council Laboratory of Molecular BiologyCambridgeCB2 0QHUK
- Present address:
Molecular Horizons and School of Chemistry and Molecular BioscienceUniversity of Wollongong & Illawarra Health and Medical Research InstituteWollongongNSW2522Australia
| | - Kirby Broderick
- School of Chemical & Biomolecular EngineeringGeorgia Institute of TechnologyAtlantaGA30332USA
| | - William R. Schafer
- Neurobiology DivisionMedical Research Council Laboratory of Molecular BiologyCambridgeCB2 0QHUK
| | - Hang Lu
- School of Chemical & Biomolecular EngineeringGeorgia Institute of TechnologyAtlantaGA30332USA
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11
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Chew YL, Tanizawa Y, Cho Y, Zhao B, Yu AJ, Ardiel EL, Rabinowitch I, Bai J, Rankin CH, Lu H, Beets I, Schafer WR. An Afferent Neuropeptide System Transmits Mechanosensory Signals Triggering Sensitization and Arousal in C. elegans. Neuron 2018; 99:1233-1246.e6. [PMID: 30146306 PMCID: PMC6162336 DOI: 10.1016/j.neuron.2018.08.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 06/22/2018] [Accepted: 08/02/2018] [Indexed: 11/05/2022]
Abstract
Sensitization is a simple form of behavioral plasticity by which an initial stimulus, often signaling danger, leads to increased responsiveness to subsequent stimuli. Cross-modal sensitization is an important feature of arousal in many organisms, yet its molecular and neural mechanisms are incompletely understood. Here we show that in C. elegans, aversive mechanical stimuli lead to both enhanced locomotor activity and sensitization of aversive chemosensory pathways. Both locomotor arousal and cross-modal sensitization depend on the release of FLP-20 neuropeptides from primary mechanosensory neurons and on their receptor FRPR-3. Surprisingly, the critical site of action of FRPR-3 for both sensory and locomotor arousal is RID, a single neuroendocrine cell specialized for the release of neuropeptides that responds to mechanical stimuli in a FLP-20-dependent manner. Thus, FLP-20 peptides function as an afferent arousal signal that conveys mechanosensory information to central neurons that modulate arousal and other behavioral states.
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Affiliation(s)
- Yee Lian Chew
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, Cambridgeshire, CB2 0QH, UK
| | - Yoshinori Tanizawa
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, Cambridgeshire, CB2 0QH, UK
| | - Yongmin Cho
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0100, USA
| | - Buyun Zhao
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, Cambridgeshire, CB2 0QH, UK
| | - Alex J Yu
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T, Canada
| | - Evan L Ardiel
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T, Canada
| | - Ithai Rabinowitch
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Department of Medical Neurobiology, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Jihong Bai
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Catharine H Rankin
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T, Canada; Department of Psychology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Hang Lu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0100, USA
| | - Isabel Beets
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge, Cambridgeshire, CB2 0QH, UK; Department of Biology, Division of Animal Physiology and Neurobiology, KU Leuven, B-3000, Leuven, Belgium
| | - William R Schafer
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, Cambridgeshire, CB2 0QH, UK.
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12
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Chew YL, Grundy LJ, Brown AEX, Beets I, Schafer WR. Neuropeptides encoded by nlp-49 modulate locomotion, arousal and egg-laying behaviours in Caenorhabditis elegans via the receptor SEB-3. Philos Trans R Soc Lond B Biol Sci 2018; 373:20170368. [PMID: 30201834 PMCID: PMC6158228 DOI: 10.1098/rstb.2017.0368] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2018] [Indexed: 12/23/2022] Open
Abstract
Neuropeptide signalling has been implicated in a wide variety of biological processes in diverse organisms, from invertebrates to humans. The Caenorhabditis elegans genome has at least 154 neuropeptide precursor genes, encoding over 300 bioactive peptides. These neuromodulators are thought to largely signal beyond 'wired' chemical/electrical synapse connections, therefore creating a 'wireless' network for neuronal communication. Here, we investigated how behavioural states are affected by neuropeptide signalling through the G protein-coupled receptor SEB-3, which belongs to a bilaterian family of orphan secretin receptors. Using reverse pharmacology, we identified the neuropeptide NLP-49 as a ligand of this evolutionarily conserved neuropeptide receptor. Our findings demonstrate novel roles for NLP-49 and SEB-3 in locomotion, arousal and egg-laying. Specifically, high-content analysis of locomotor behaviour indicates that seb-3 and nlp-49 deletion mutants cause remarkably similar abnormalities in movement dynamics, which are reversed by overexpression of wild-type transgenes. Overexpression of NLP-49 in AVK interneurons leads to heightened locomotor arousal, an effect that is dependent on seb-3. Finally, seb-3 and nlp-49 mutants also show constitutive egg-laying in liquid medium and alter the temporal pattern of egg-laying in similar ways. Together, these results provide in vivo evidence that NLP-49 peptides act through SEB-3 to modulate behaviour, and highlight the importance of neuropeptide signalling in the control of behavioural states.This article is part of a discussion meeting issue 'Connectome to behaviour: modelling C. elegans at cellular resolution'.
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Affiliation(s)
- Yee Lian Chew
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Laura J Grundy
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - André E X Brown
- MRC London Institute of Medical Sciences, London W12 0NN, UK
- Institute of Clinical Sciences, Imperial College London, London W12 0NN, UK
| | - Isabel Beets
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
- Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - William R Schafer
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
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13
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Towlson EK, Vértes PE, Yan G, Chew YL, Walker DS, Schafer WR, Barabási AL. Caenorhabditis elegans and the network control framework-FAQs. Philos Trans R Soc Lond B Biol Sci 2018; 373:20170372. [PMID: 30201837 PMCID: PMC6158218 DOI: 10.1098/rstb.2017.0372] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2018] [Indexed: 12/31/2022] Open
Abstract
Control is essential to the functioning of any neural system. Indeed, under healthy conditions the brain must be able to continuously maintain a tight functional control between the system's inputs and outputs. One may therefore hypothesize that the brain's wiring is predetermined by the need to maintain control across multiple scales, maintaining the stability of key internal variables, and producing behaviour in response to environmental cues. Recent advances in network control have offered a powerful mathematical framework to explore the structure-function relationship in complex biological, social and technological networks, and are beginning to yield important and precise insights on neuronal systems. The network control paradigm promises a predictive, quantitative framework to unite the distinct datasets necessary to fully describe a nervous system, and provide mechanistic explanations for the observed structure and function relationships. Here, we provide a thorough review of the network control framework as applied to Caenorhabditis elegans (Yan et al. 2017 Nature550, 519-523. (doi:10.1038/nature24056)), in the style of Frequently Asked Questions. We present the theoretical, computational and experimental aspects of network control, and discuss its current capabilities and limitations, together with the next likely advances and improvements. We further present the Python code to enable exploration of control principles in a manner specific to this prototypical organism.This article is part of a discussion meeting issue 'Connectome to behaviour: modelling C. elegans at cellular resolution'.
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Affiliation(s)
- Emma K Towlson
- Center for Complex Network Research and Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Petra E Vértes
- Department of Psychiatry, Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge CB2 0SZ, UK
| | - Gang Yan
- Center for Complex Network Research and Department of Physics, Northeastern University, Boston, MA 02115, USA
- School of Physics Science and Engineering, Tongji University, Shanghai 200092, People's Republic of China
| | - Yee Lian Chew
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Denise S Walker
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - William R Schafer
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Albert-László Barabási
- Center for Complex Network Research and Department of Physics, Northeastern University, Boston, MA 02115, USA
- Center for Cancer Systems Biology, Dana Farber Cancer Institute, Boston, MA 02115, USA
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
- Center for Network Science, Central European University, Budapest 1051, Hungary
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14
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Yan G, Vértes PE, Towlson EK, Chew YL, Walker DS, Schafer WR, Barabási AL. Network control principles predict neuron function in the Caenorhabditis elegans connectome. Nature 2017; 550:519-523. [PMID: 29045391 PMCID: PMC5710776 DOI: 10.1038/nature24056] [Citation(s) in RCA: 163] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 09/04/2017] [Indexed: 12/21/2022]
Abstract
Recent studies on the controllability of complex systems offer a powerful mathematical framework to systematically explore the structure-function relationship in biological, social, and technological networks. Despite theoretical advances, we lack direct experimental proof of the validity of these widely used control principles. Here we fill this gap by applying a control framework to the connectome of the nematode Caenorhabditis elegans, allowing us to predict the involvement of each C. elegans neuron in locomotor behaviours. We predict that control of the muscles or motor neurons requires 12 neuronal classes, which include neuronal groups previously implicated in locomotion by laser ablation, as well as one previously uncharacterized neuron, PDB. We validate this prediction experimentally, finding that the ablation of PDB leads to a significant loss of dorsoventral polarity in large body bends. Importantly, control principles also allow us to investigate the involvement of individual neurons within each neuronal class. For example, we predict that, within the class of DD motor neurons, only three (DD04, DD05, or DD06) should affect locomotion when ablated individually. This prediction is also confirmed; single cell ablations of DD04 or DD05 specifically affect posterior body movements, whereas ablations of DD02 or DD03 do not. Our predictions are robust to deletions of weak connections, missing connections, and rewired connections in the current connectome, indicating the potential applicability of this analytical framework to larger and less well-characterized connectomes.
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Affiliation(s)
- Gang Yan
- Center for Complex Network Research and Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA
- School of Physics Science and Engineering, Tongji University, Shanghai 200092, P. R. China
| | - Petra E. Vértes
- Department of Psychiatry, Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge CB2 0SZ UK
| | - Emma K. Towlson
- Center for Complex Network Research and Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA
| | - Yee Lian Chew
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Denise S. Walker
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - William R. Schafer
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Albert-László Barabási
- Center for Complex Network Research and Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA
- Center for Cancer Systems Biology, Dana Farber Cancer Institute, Boston, Massachusetts 02115, USA
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
- Center for Network Science, Central European University, H-1051 Budapest, Hungary
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15
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Abstract
A map of a neuronal circuit in a marine worm reveals how simple networks of neurons can control behavior.
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Affiliation(s)
- Yee Lian Chew
- MRC Laboratory of Molecular Biology, University of Cambridge, Cambridge, United Kingdom
| | - William R Schafer
- MRC Laboratory of Molecular Biology, University of Cambridge, Cambridge, United Kingdom
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16
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Bentley B, Branicky R, Barnes CL, Chew YL, Yemini E, Bullmore ET, Vértes PE, Schafer WR. The Multilayer Connectome of Caenorhabditis elegans. PLoS Comput Biol 2016; 12:e1005283. [PMID: 27984591 PMCID: PMC5215746 DOI: 10.1371/journal.pcbi.1005283] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 01/04/2017] [Accepted: 12/05/2016] [Indexed: 11/17/2022] Open
Abstract
Connectomics has focused primarily on the mapping of synaptic links in the brain; yet it is well established that extrasynaptic volume transmission, especially via monoamines and neuropeptides, is also critical to brain function and occurs primarily outside the synaptic connectome. We have mapped the putative monoamine connections, as well as a subset of neuropeptide connections, in C. elegans based on new and published gene expression data. The monoamine and neuropeptide networks exhibit distinct topological properties, with the monoamine network displaying a highly disassortative star-like structure with a rich-club of interconnected broadcasting hubs, and the neuropeptide network showing a more recurrent, highly clustered topology. Despite the low degree of overlap between the extrasynaptic (or wireless) and synaptic (or wired) connectomes, we find highly significant multilink motifs of interaction, pinpointing locations in the network where aminergic and neuropeptide signalling modulate synaptic activity. Thus, the C. elegans connectome can be mapped as a multiplex network with synaptic, gap junction, and neuromodulator layers representing alternative modes of interaction between neurons. This provides a new topological plan for understanding how aminergic and peptidergic modulation of behaviour is achieved by specific motifs and loci of integration between hard-wired synaptic or junctional circuits and extrasynaptic signals wirelessly broadcast from a small number of modulatory neurons.
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Affiliation(s)
- Barry Bentley
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Robyn Branicky
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Christopher L. Barnes
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
- HHMI Janelia Research Campus, Ashburn, VA, United States of America
| | - Yee Lian Chew
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Eviatar Yemini
- Department of Biological Sciences, Columbia University, New York, NY, United States of America
| | - Edward T. Bullmore
- Department of Psychiatry, University of Cambridge, Cambridge United Kingdom
- ImmunoPsychiatry, Alternative Discovery & Development, GlaxoSmithKline R&D, Cambridge United Kingdom
| | - Petra E. Vértes
- Department of Psychiatry, University of Cambridge, Cambridge United Kingdom
| | - William R. Schafer
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
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17
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Chew YL, Schafer WR. Dopamine helps worms deal with stress. EMBO J 2016; 35:1851-2. [PMID: 27440403 DOI: 10.15252/embj.201695010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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18
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Berber S, Wood M, Llamosas E, Thaivalappil P, Lee K, Liao BM, Chew YL, Rhodes A, Yucel D, Crossley M, Nicholas HR. Homeodomain-Interacting Protein Kinase (HPK-1) regulates stress responses and ageing in C. elegans. Sci Rep 2016; 6:19582. [PMID: 26791749 PMCID: PMC4726358 DOI: 10.1038/srep19582] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 12/15/2015] [Indexed: 11/22/2022] Open
Abstract
Proteins of the Homeodomain-Interacting Protein Kinase (HIPK) family regulate an array of processes in mammalian systems, such as the DNA damage response, cellular proliferation and apoptosis. The nematode Caenorhabditis elegans has a single HIPK homologue called HPK-1. Previous studies have implicated HPK-1 in longevity control and suggested that this protein may be regulated in a stress-dependent manner. Here we set out to expand these observations by investigating the role of HPK-1 in longevity and in the response to heat and oxidative stress. We find that levels of HPK-1 are regulated by heat stress, and that HPK-1 contributes to survival following heat or oxidative stress. Additionally, we show that HPK-1 is required for normal longevity, with loss of HPK-1 function leading to a faster decline of physiological processes that reflect premature ageing. Through microarray analysis, we have found that HPK-1-regulated genes include those encoding proteins that serve important functions in stress responses such as Phase I and Phase II detoxification enzymes. Consistent with a role in longevity assurance, HPK-1 also regulates the expression of age-regulated genes. Lastly, we show that HPK-1 functions in the same pathway as DAF-16 to regulate longevity and reveal a new role for HPK-1 in development.
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Affiliation(s)
- Slavica Berber
- School of Molecular Bioscience, University of Sydney, Sydney, Australia
| | - Mallory Wood
- School of Molecular Bioscience, University of Sydney, Sydney, Australia
| | - Estelle Llamosas
- School of Molecular Bioscience, University of Sydney, Sydney, Australia
| | | | - Karen Lee
- School of Molecular Bioscience, University of Sydney, Sydney, Australia
| | - Bing Mana Liao
- School of Molecular Bioscience, University of Sydney, Sydney, Australia
| | - Yee Lian Chew
- School of Molecular Bioscience, University of Sydney, Sydney, Australia
| | - Aaron Rhodes
- School of Molecular Bioscience, University of Sydney, Sydney, Australia
| | - Duygu Yucel
- School of Molecular Bioscience, University of Sydney, Sydney, Australia
| | - Merlin Crossley
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, Australia
| | - Hannah R Nicholas
- School of Molecular Bioscience, University of Sydney, Sydney, Australia
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19
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Chew YL, Götz J, Nicholas HR. Neuronal protein with tau-like repeats (PTL-1) regulates intestinal SKN-1 nuclear accumulation in response to oxidative stress. Aging Cell 2015; 14:148-51. [PMID: 25399685 PMCID: PMC4326904 DOI: 10.1111/acel.12285] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/07/2014] [Indexed: 11/29/2022] Open
Abstract
Oxidative stress is a central pathomechanism in Alzheimer's disease (AD) and other diseases with tau pathology. The Nrf2 transcription factor induces detoxification enzymes and improves tau pathology and cognition. Its homologue in C. elegans is SKN-1. We previously showed that the worm tau homologue, PTL-1, regulates neuronal aging and lifespan. Here, we tested PTL-1's involvement in the stress response. ptl-1 mutant animals are hypersensitive to oxidative stress and are defective in stress-mediated nuclear accumulation of SKN-1. This defect can be rescued by PTL-1 re-expression under the control of the ptl-1 promoter. Given the close relationship between aging and stress tolerance, we tested lifespan and found that PTL-1 and SKN-1 regulate longevity via similar processes. Our data also suggest that PTL-1 functions via neurons to modulate SKN-1, clarifying the role of this protein in the stress response and longevity.
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Affiliation(s)
- Yee Lian Chew
- School of Molecular Bioscience University of Sydney Sydney NSW Australia
| | - Jürgen Götz
- Clem Jones Centre for Ageing Dementia Research (CJCADR) at the Queensland Brain Institute (QBI) University of Queensland Brisbane (St Lucia campus) QLD Australia
| | - Hannah R. Nicholas
- School of Molecular Bioscience University of Sydney Sydney NSW Australia
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20
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Chew YL, Fan X, Götz J, Nicholas HR. Regulation of age-related structural integrity in neurons by protein with tau-like repeats (PTL-1) is cell autonomous. Sci Rep 2014; 4:5185. [PMID: 24898126 PMCID: PMC4046136 DOI: 10.1038/srep05185] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 05/15/2014] [Indexed: 11/09/2022] Open
Abstract
PTL-1 is the sole homolog of the MAP2/MAP4/tau family in Caenorhabditis elegans. Accumulation of tau is a pathological hallmark of neurodegenerative diseases such as Alzheimer's disease. Therefore, reducing tau levels has been suggested as a therapeutic strategy. We previously showed that PTL-1 maintains age-related structural integrity in neurons, implying that excessive reduction in the levels of a tau-like protein is detrimental. Here, we demonstrate that the regulation of neuronal ageing by PTL-1 occurs via a cell-autonomous mechanism. We re-expressed PTL-1 in a null mutant background using a pan-neuronal promoter to show that PTL-1 functions in neurons to maintain structural integrity. We next expressed PTL-1 only in touch neurons and showed rescue of the neuronal ageing phenotype of ptl-1 mutant animals in these neurons but not in another neuronal subset, the ventral nerve cord GABAergic neurons. Knockdown of PTL-1 in touch neurons also resulted in premature neuronal ageing in these neurons but not in GABAergic neurons. Additionally, expression of PTL-1 in touch neurons alone was unable to rescue the shortened lifespan observed in ptl-1 mutants, but pan-neuronal re-expression restored wild-type longevity, indicating that, at least for a specific group of mechanosensory neurons, premature neuronal ageing and organismal ageing can be decoupled.
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Affiliation(s)
- Yee Lian Chew
- 1] School of Molecular Bioscience, University of Sydney, Australia [2]
| | - Xiaochen Fan
- 1] School of Molecular Bioscience, University of Sydney, Australia [2]
| | - Jürgen Götz
- Clem Jones Centre for Ageing Dementia Research (CJCADR) at the Queensland Brain Institute (QBI), University of Queensland, Australia
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21
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Liang V, Ullrich M, Lam H, Chew YL, Banister S, Song X, Zaw T, Kassiou M, Götz J, Nicholas HR. Altered proteostasis in aging and heat shock response in C. elegans revealed by analysis of the global and de novo synthesized proteome. Cell Mol Life Sci 2014; 71:3339-61. [PMID: 24458371 PMCID: PMC4131143 DOI: 10.1007/s00018-014-1558-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 12/18/2013] [Accepted: 01/03/2014] [Indexed: 01/22/2023]
Abstract
Protein misfolding and aggregation as a consequence of impaired protein homeostasis (proteostasis) not only characterizes numerous age-related diseases but also the aging process itself. Functionally related to the aging process are, among others, ribosomal proteins, suggesting an intimate link between proteostasis and aging. We determined by iTRAQ quantitative proteomic analysis in C. elegans how the proteome changes with age and in response to heat shock. Levels of ribosomal proteins and mitochondrial chaperones were decreased in aged animals, supporting the notion that proteostasis is altered during aging. Mitochondrial enzymes of the tricarboxylic acid cycle and the electron transport chain were also reduced, consistent with an age-associated energy impairment. Moreover, we observed an age-associated decline in the heat shock response. In order to determine how protein synthesis is altered in aging and in response to heat shock, we complemented our global analysis by determining the de novo proteome. For that, we established a novel method that enables both the visualization and identification of de novo synthesized proteins, by incorporating the non-canonical methionine analogue, azidohomoalanine (AHA), into the nascent polypeptides, followed by reacting the azide group of AHA by ‘click chemistry’ with an alkyne-labeled tag. Our analysis of AHA-tagged peptides demonstrated that the decreased abundance of, for example, ribosomal proteins in aged animals is not solely due to degradation but also reflects a relative decrease in their synthesis. Interestingly, although the net rate of protein synthesis is reduced in aged animals, our analyses indicate that the synthesis of certain proteins such as the vitellogenins increases with age.
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Affiliation(s)
- Vanessa Liang
- Brain and Mind Research Institute, University of Sydney, Camperdown, 2050, Australia
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22
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Chew YL, Fan X, Götz J, Nicholas HR. Aging in the nervous system of Caenorhabditis elegans. Commun Integr Biol 2013; 6:e25288. [PMID: 24255742 PMCID: PMC3829903 DOI: 10.4161/cib.25288] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 06/04/2013] [Accepted: 06/05/2013] [Indexed: 11/28/2022] Open
Abstract
It has recently been described that aging in C. elegans is accompanied by the progressive development of morphological changes in the nervous system. These include novel outgrowths from the cell body or axonal process, as well as blebbing and beading along the length of the axon. The formation of these structures is regulated by numerous molecular players including members of the well-conserved insulin/insulin growth factor-like (IGF)-1 signaling and mitogen-activated protein (MAP) kinase pathways. This review summarizes the recent literature on neuronal aging in C. elegans, including our own findings, which indicate a role for protein with tau-like repeats (PTL-1), the homolog of mammalian tau and MAP2/4, in maintaining neuronal integrity during aging.
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Affiliation(s)
- Yee Lian Chew
- School of Molecular Bioscience; University of Sydney; Sydney, NSW Australia
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23
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Abstract
TAU is a microtubule-associated protein that under pathological conditions such as Alzheimer's disease (AD) forms insoluble, filamentous aggregates. When 20 years after TAU's discovery the first TAU transgenic mouse models were established, one declared goal that was achieved was the modeling of authentic TAU aggregate formation in the form of neurofibrillary tangles. However, as we review here, it has become increasingly clear that TAU causes damage much before these filamentous aggregates develop. In fact, because TAU is a scaffolding protein, increased levels and an altered subcellular localization (due to an increased insolubility and impaired clearance) result in the interaction of TAU with cellular proteins with which it would otherwise either not interact or do so to a lesser degree, thereby impairing their physiological functions. We specifically discuss the non-axonal localization of TAU, the role phosphorylation has in TAU toxicity and how TAU impairs mitochondrial functions. A major emphasis is on what we have learned from the four available TAU knock-out models in mice, and the knock-out of the TAU/MAP2 homolog PTL-1 in worms. It has been proposed that in human pathological conditions such as AD, a rare toxic TAU species exists which needs to be specifically removed to abrogate TAU's toxicity and restore neuronal functions. However, what is toxic in one context may not be in another, and simply reducing, but not fully abolishing TAU levels may be sufficient to abrogate TAU toxicity.
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Affiliation(s)
- Jürgen Götz
- Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
- Sydney Medical School, Brain and Mind Research Institute, University of Sydney, Sydney, NSW, Australia
| | - Di Xia
- Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Gerhard Leinenga
- Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Yee Lian Chew
- School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia
| | - Hannah R. Nicholas
- School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia
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24
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Abstract
Protein with tau-like repeats (PTL-1) is the sole Caenorhabditis elegans homolog of tau and MAP2, which are members of the mammalian family of microtubule-associated proteins (MAPs). In mammalian neurons, tau and MAP2 are segregated, with tau being mainly localised to the axon and MAP2 mainly to the dendrite. In particular, tau plays a crucial role in pathology, as elevated levels lead to the formation of tau aggregates in many neurodegenerative conditions including Alzheimer's disease. We used PTL-1 in C. elegans to model the biological functions of a tau-like protein without the complication of functional redundancy that is observed among the mammalian MAPs. Our findings indicate that PTL-1 is important for the maintenance of neuronal health as animals age, as well as in the regulation of whole organism lifespan. In addition, gene dosage of PTL-1 is crucial because variations from wild-type levels are detrimental. We also observed that human tau is unable to robustly compensate for loss of PTL-1, although phenotypes observed in tau transgenic worms are dependent on the presence of endogenous PTL-1. Our data suggest that some of the effects of tau pathology result from the loss of physiological tau function and not solely from a toxic gain-of-function due to accumulation of tau.
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Affiliation(s)
- Yee Lian Chew
- School of Molecular Bioscience, University of Sydney, New South Wales, 2006, Australia
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25
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Lynn H, Horsington J, Ter LK, Han S, Chew YL, Diefenbach RJ, Way M, Chaudhri G, Karupiah G, Newsome TP. Loss of cytoskeletal transport during egress critically attenuates ectromelia virus infection in vivo. J Virol 2012; 86:7427-43. [PMID: 22532690 PMCID: PMC3416336 DOI: 10.1128/jvi.06636-11] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 03/30/2012] [Indexed: 12/18/2022] Open
Abstract
Egress of wrapped virus (WV) to the cell periphery following vaccinia virus (VACV) replication is dependent on interactions with the microtubule motor complex kinesin-1 and is mediated by the viral envelope protein A36. Here we report that ectromelia virus (ECTV), a related orthopoxvirus and the causative agent of mousepox, encodes an A36 homologue (ECTV-Mos-142) that is highly conserved despite a large truncation at the C terminus. Deleting the ECTV A36R gene leads to a reduction in the number of extracellular viruses formed and to a reduced plaque size, consistent with a role in microtubule transport. We also observed a complete loss of virus-associated actin comets, another phenotype dependent on A36 expression during VACV infection. ECTV ΔA36R was severely attenuated when used to infect the normally susceptible BALB/c mouse strain. ECTV ΔA36R replication and spread from the draining lymph nodes to the liver and spleen were significantly reduced in BALB/c mice and in Rag-1-deficient mice, which lack T and B lymphocytes. The dramatic reduction in ECTV ΔA36R titers early during the course of infection was not associated with an augmented immune response. Taken together, these findings demonstrate the critical role that subcellular transport pathways play not only in orthopoxvirus infection in an in vitro context but also during orthopoxvirus pathogenesis in a natural host. Furthermore, despite the attenuation of the mutant virus, we found that infection nonetheless induced protective immunity in mice, suggesting that orthopoxvirus vectors with A36 deletions may be considered another safe vaccine alternative.
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Affiliation(s)
- Helena Lynn
- School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia
| | | | - Lee Kuan Ter
- John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Shuyi Han
- School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia
| | - Yee Lian Chew
- School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia
| | - Russell J. Diefenbach
- Centre for Virus Research, The Westmead Millennium Institute, University of Sydney, Westmead, NSW, Australia
| | - Michael Way
- Cancer Research UK, Lincoln's Inn Fields Laboratories, London, United Kingdom
| | - Geeta Chaudhri
- John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Gunasegaran Karupiah
- John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Timothy P. Newsome
- School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia
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Lim YC, Chia KS, Ong HY, Ng V, Chew YL. Renal dysfunction in workers exposed to inorganic lead. Ann Acad Med Singap 2001; 30:112-7. [PMID: 11379406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
INTRODUCTION We studied the relationship between renal dysfunction and occupational lead exposure in a local factory. MATERIALS AND METHODS A cross-sectional study with a cohort component was conducted with 55 male workers of a factory producing PVC stabilisers as subjects. Workers from this factory have been followed up with 6-monthly blood lead measurements since 1982. Two indices of overall lead exposure, i.e. the number of times a worker's blood lead exceeded 40 micrograms/dL (PbB40) and cumulative blood lead index (PbBint), were obtained from this data. Recent blood lead concentration (PbB) was measured. 4-hour creatinine clearance and various other urinary and serum markers of renal dysfunction were used as effect indices. RESULTS There was no relationship between PbB and any of the renal markers. However, creatinine clearance decreased significantly (P < 0.001) with increasing PbB40 and PbBint after adjustment for age and smoking habits. Urinary albumin (Ualb), urinary alpha-1 microglobulin (U alpha 1m), urinary beta-2 microglobulin (U beta 2m) and urinary retinol-binding protein (URBP) increased significantly with both increasing PbB40 and PbBint. Total urinary activity of N-acetyl-beta-D-glucosaminidase (NAG-T) and its heat-stable isoenzyme (NAG-B) increased significantly with increasing PbB40. A significant difference in renal parameters occurred when PbB40 was 1 or more. CONCLUSIONS We have found a positive association between overall lead exposure and renal dysfunction. The renal parameters were significantly higher among those who had at least one episode of blood lead above 40 micrograms/dL. Our findings also strengthen the case for the use of Ualb, U alpha 1m, U beta 2m, URBP, NAG-T and NAG-B as early markers of lead nephropathy.
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Affiliation(s)
- Y C Lim
- Faculty of Medicine, National University of Singapore, MD3, Lower Kent Ridge Road, Singapore 119260
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